CN1022327C

CN1022327C - Weather-resistant polyacetal resin composition

Info

Publication number: CN1022327C
Application number: CN90107262A
Authority: CN
Inventors: 胜亦彻
Original assignee: Polyplastics Co Ltd
Current assignee: Polyplastics Co Ltd
Priority date: 1989-08-10
Filing date: 1990-08-10
Publication date: 1993-10-06
Anticipated expiration: 2005-08-10
Also published as: CA2022969A1; EP0412840A2; BR9003927A; US5118734A; EP0412840A3; CN1049855A; KR930010231B1; KR910004737A

Abstract

A polyacetal composition comprising 45 to 98.89% by weight of a polyacetal, (B)0.01 to 5% by weight of a weather (light) stabilizer, (C)1 to 40% by weight of an acrylate resin, and (D)0.1 to 10% by weight of a polymer having an oxyalkylene unit having 2 to 8 carbon atoms among oxyalkylene units, is improved in weather resistance.

Description

Weather-resistant polyacetal resin composition

The present invention relates to a kind of polyacetal resin composite with remarkable Weather-resistant.Particularly, the invention provides a kind of polyacetal resin composite with unsurpassed Weather-resistant, it is to make by weather (light) stablizer, acrylate resin and a kind of specific oxyalkylene polymer are added to polyacetal resin.The present invention provides the moulded product by this polyacetal resin composite form simultaneously.

As everyone knows, as the engineering plastics of the chemical property (such as chemical resistant properties and thermotolerance) with remarkable physicals (such as mechanics and electrical property) or brilliance, polyacetal resin is used to many fields in recent years.Yet the expansion along with using the polyacetal resin field requires this material to have some other peculiar properties.Need or relevant Weather-resistant aspect these special performances, further improvement is arranged.Particularly under envrionment conditions such as sunlight, luminescent lamp, rainwater and the air influence of its use, problem easily takes place in the component of the inside of automobile or exterior part and appliances, for example fades, the reduction of surface finish (it causes its glossy to disappear), produces be full of cracks and make its appearance damage at piece surface.In order to overcome these shortcomings, people advised already, improved anti-weather (light) aging of polyacetal resin by adding all weathers (light) stablizer therein.

Yet the method that adds stablizer therein is always not gratifying, and requires more remarkable weather (light) stability.

Although can obtain some effects aspect its anti-weather (light) aging by weather (light) stablizer and acrylate resin being added in the polyacetal resin improving, but outdoor be exposed to sunlight (ultraviolet ray), rainwater etc. for a long time after, surface appearance of moulded product (be full of cracks, gloss etc.) and mechanical property are always not gratifying.Therefore, often require further to improve its anti-weather (light) aging.

Even when only increasing the consumption of weather (light) stablizer, acrylate resin or other congeners, also be limited in the raising aspect anti-weather (light) aging.In addition, the increase of additive capacity can slacken mechanical property (as tensile strength and cantilever-type impact strength).In addition, stablizer can make the release property variation or adhere on the mould and form mold deposit when molding, causes dimensional precision to reduce or influence the outward appearance of moulded product thus, causes the increase of mould scavenging period and reduces molded operation efficient.Therefore traditional working method still exists shortcoming and problem.

In order further to improve weather (light) stability that is used for outdoor polyacetal resin and don't the requisite performance of losing polyacetal resin, the contriver is doing to have finished the present invention after the deep research.

In the present invention, polyacetal composition comprises the acrylate resin and (D) the oxyalkylene units polymkeric substance that contains 2-8 carbon atom in its oxyalkylene units of 0.1-10% weight of weather (light) stablizer, (C) 1-40% weight of polyacetal, (B) 0.01-5% weight of (A) 45-98.89% weight, and this composition is improved aspect Weather-resistant.Composition preferably contains the polymkeric substance (D) of 1-10% weight.

Being used for polyacetal resin of the present invention (A) is a kind of aerobic methylene radical (CH that contains ₂O-) polymkeric substance of the main component units of conduct.It can be any polyoxymethylene homopolymer and multipolymer, trimer and the segmented copolymer that still contains the polyoxymethylene of a small amount of other component units except the oxidation methylene radical.The molecule of polyacetal resin (A) not only can have linear structure, and can have branched structure or crosslinking structure.The polymerization degree for polyacetal resin (A) has no particular limits.

In being applicable to weather of the present invention (light) stablizer, best is that one or more are selected from the compound in (1) benzotriazole category, (2) benzophenone, (3) aromatic benzoate class, (4) cyanoacrylate, (5) oxalic dianilide class and (6) hindered amines.

Their example is as follows:

(1) benzotriazole category: 2-(2 ' hydroxyl-5 '-tolyl)-benzotriazole, 2-(2 ' hydroxyl-3 ', 5 '-di-tert-butyl-phenyl) benzotriazole, 2-(35-two tert-pentyls-2-hydroxyphenyl) benzotriazole, 2-(2 '-hydroxyl-3 ', 5 '-the diisoamyl phenyl) benzotriazole, 2-(2-hydroxyl-3, two (a, the a-dimethyl benzyl) phenyl of 5-) benzotriazole and 2-(2 '-hydroxyl-4 '-octyloxyphenyl) benzotriazole;

(2) benzophenone: 2,4-dihydroxy benaophenonel, 2-hydroxyl-4-methoxy benzophenone, 2-hydroxyl-4-octyloxy benzophenone, 2-hydroxyl-4-dodecyloxy benzophenone, 2,2 '-dihydroxyl-4-methoxy benzophenone, 2,2 '-dihydroxyl-4,4 '-dimethoxy-benzophenone, 2-hydroxyl-4-methoxyl group-5-diphenylsulfone ketone and 2-hydroxyl-4-oxygen benzyl benzophenone;

(3) aromatic benzoate class: p-t-butylphenyl salicylate and p-octylphenyl salicylate;

(4) cyanoacrylate: 2-cyano group-3,3 '-diphenylacrylate 2-ethylhexyl and 2-cyano group-3,3 '-diphenyl-ethyl acrylate;

(5) oxalic dianilide class: N-(2-ethylphenyl)-N '-(2-oxyethyl group-5-tert-butyl-phenyl) oxalamide and N-(2-ethylphenyl)-N '-(2-phenelyl) oxalamide.

Herein the hindered amine of Shi Yonging (6) be have the space be obstructed the base piperidine derivative, as 4-acetoxyl group-2,2,6, the 6-tetramethyl piperidine, 4-stearoyl-oxy-2,2,6, the 6-tetramethyl piperidine, 4-acryloxy-2,2,6, the 6-tetramethyl piperidine, 4-methoxyl group-2,2,6, the 6-tetramethyl piperidine, 4-benzoyloxy-2,2,6, the 6-tetramethyl piperidine, 4-cyclohexyloxy-2,2,6, the 6-tetramethyl piperidine, 4-phenoxy group-2,2,6, the 6-tetramethyl piperidine, 4-benzyloxy-2,2,6, the 6-tetramethyl piperidine, 4-(phenyl amino methanoyl)-2,2,6, the 6-tetramethyl piperidine, oxalic acid two (2,2,6,6-tetramethyl--4-piperidines) ester, propanedioic acid two (2,2,6,6-tetramethyl--4-piperidines) ester, hexanodioic acid two (2,2,6,6-tetramethyl--4-piperidines) ester, sebacic acid two (2,2,6,6-tetramethyl--4-piperidines) ester, sebacic acid two (1,2,2,6,6-pentamethyl-piperidines) ester, terephthalic acid two (2,2,6,6-tetramethyl--4-piperidines) ester, 1,2-two (2,2,6,6-tetramethyl--4-piperidines oxygen base) ethane, hexa-methylene-1,6-diamino acid two (2,2,6,6-tetramethyl--4-piperidyl) ester, two (the 1-methyl-2 of hexanodioic acid, 2,6,6-tetramethyl--4-piperidines) ester and benzene-1,3,5-tricarboxylic acid three (2,2,6,6-tetramethyl--4-piperidines) ester.By the polycondensate of high molecular piperidine derivatives Succinic acid dimethylester/1-(2-hydroxyethyl)-4-hydroxyl-2,2,6 for example, the polycondensate of 6-tetramethyl piperidine also can use.

These weathers (light) stablizer can use separately or preferably two or more be used together.Particularly preferably in weather stablizer (1)-(5) one or more are used with hindered amine (6).

The consumption of weather (light) stablizer (B) is that benchmark is counted 0.01-5% weight with whole composition, particularly 0.02-3% weight.When the usefulness quantity not sufficient of stablizer, do not reach expected effect; Otherwise stablizer is excessive then uneconomical, but also can cause such as problems such as mechanical property variation and pollution moulds.

The acrylate resin that the present invention is suitable for comprises vinylformic acid, acrylate (methyl acrylate for example, ethyl propenoate, the vinylformic acid n-propyl, isopropyl acrylate, n-butyl acrylate, just own ester of vinylformic acid and vinylformic acid n-octyl), methacrylic acid, methacrylic ester (methyl methacrylate for example, Jia Jibingxisuanyizhi, n propyl methacrylate, isopropyl methacrylate, n-BMA, Propenoic acid, 2-methyl, isobutyl ester, methacrylic acid n-pentyl ester and n octyl methacrylate) homopolymer; They and for example multipolymer of vinylbenzene, vinyl cyanide, divinyl or isoprene.In these polymkeric substance, preferably use the homopolymer of methyl methacrylate and comprise as the methyl methacrylate of main ingredient and the multipolymer of acrylate, methacrylic ester (not being methyl methacrylate), vinylbenzene or vinyl cyanide.

The consumption of acrylate resin (C) is a benchmark in whole composition in addition, is 1-40%, particularly 5-30% weight.When acrylate resin (C) use quantity not sufficient the time, then its anti-weather (light) solarization is not obvious, does not particularly demonstrate to prevent that molded article surface from the ability of be full of cracks taking place; On the contrary, when its consumption is excessive, then mechanical property and thermostability there is bad influence.

Although anti-weather (light) aging is improved by acrylate resin (C) and share of weather (light) stablizer (B), but anti-weather (light) aging is still not ideal enough, and the problems referred to above such as mechanical property and mouldability variation problem are also still unresolved.

Therefore, composition of the present invention is characterised in that it is except containing above-mentioned (A), (B) and (C) also containing the polymkeric substance (D) of the oxyalkylene that its carbochain is made up of 2-8 adjoining carbons the component.The contriver finds, (A), (B), (C) and (D) composition of four kinds of components can improve anti-weather (light) aging (particularly keep gloss and prevent be full of cracks) very effectively, and do not slacken other requisite performances of polyacetal resin.

The examples of polymers that is used in the present invention achieving the above object, contain the oxyalkylene of the carbochain of being made up of 2-8 adjoining carbons comprises polyethylene oxide, poly(propylene oxide), poly-1,2-butylene oxide ring, polyoxy heterocycle pentane, Ju oxane, polyoxy heterocycle heptane, polyoxy heterocycle octane and polyoxy heterocycle nonane, but also comprise the multipolymer of oxyethane/1,2 epoxy prapane and the multipolymer of oxyethane/tetrahydrofuran.The multipolymer here refers to random copolymers, segmented copolymer, graft copolymer and their mixture.The number-average molecular weight of used oxyalkylene polymer is 500-200000,4000-50000 preferably.Among them, its carbochain is preferred by the polymkeric substance quilt of the oxyalkylene that 2-4 adjoining carbons are formed.They comprise polyethylene oxide, poly(propylene oxide), gather 1,2-butylene oxide ring, polyoxy heterocycle pentane and oxyethane/1,2 epoxy prapane multipolymer.Wherein polyethylene oxide, poly(propylene oxide) and oxyethane/1,2 epoxy prapane multipolymer is by preferred.

The consumption of oxyalkylene polymer (D) is counted 0.1-10% weight with the weight of whole composition, particularly preferably is 2-6% weight.When consumption was less than 0.1 weight, the improvement of Weather-resistant was also little; Otherwise, when consumption surpasses 10% weight, then improve effect and reached saturated, and the key property of polyacetal resin is had adverse influence.

Though ought separately oxyalkylene polymer (D) be added in the polyacetal resin, or with weather (light) stablizer (B) or when being added in the polyacetal resin with acrylate resin (C), Weather-resistant does not significantly improve, but when using the combination of (B+C+D) three kinds of components, preventing that molded article surface from forming be full of cracks, keeping the glossiness of moulded product and reduce aspect such as fading extent for a long time, demonstrates tangible synergistic effect.

According to conjecture, obtaining of this synergistic effect is because oxyalkylene polymer can compatiblely with polyacetal resin (A) mix, again can be compatible with acrylate resin (C) so, and can improve the flowability of acrylate resin (C), thereby help resin (C) concentrating in molded article surface.As a result of be, only use a spot of acrylate resin that Weather-resistant is significantly improved, in addition, tensile strength and cantilever-type impact strength etc. also improves.

Composition of the present invention wishes also to contain known stablizer in addition so that further improve its thermostability etc.For this reason, it is desirable to use a kind of or use two or more to be selected from material in known oxidation inhibitor, nitrogenous compound and basic metal or the alkaline earth metal compound.

Composition of the present invention can be coloured to and has required color by suitably adding carbon black, dyestuff or pigment.

It is effective especially that weather (light) stablizer and sooty are combined in the stable aspect of further raising weather (light).

Composition of the present invention can contain known various additive in addition to obtain according to service condition and required performance.These additives comprise for example lubricant, nucleating agent, releasing agent, static inhibitor, tensio-active agent, organic polymer material, and inorganic or organic fibrous, particulate state or laminal filler.These additives both can use separately, also can combine use with two or more.

Composition of the present invention can use known device commonly used when making compound resin composition to prepare with known method.In this method, the component of necessity is mixed, then mixture to be mediated and extruded with single screw rod or twin screw extruder and form pellet, pellet is become moulded product by model.With mould machine preparation of compositions and molding are carried out simultaneously.In another approach, the part of all resins component is pulverized earlier to quicken the dispersion or the mixing of component, then each component is mixed and melt extrude and obtain pellet.

Stablizer and additive can add it in arbitrary step of preparation process.Certainly they also can just be added into it before producing moulded product.

Resin combination of the present invention can adopt extrusion molding, injection moulding, compression moulding, vacuum forming, blowing and foam-formed etc. in any method carry out moulding.

Form, contain weather (light) stablizer and the specific acrylate resin and the present composition of oxyalkylene polymer that are blended in wherein have tangible influence to the surface appearance of moulded product by polyacetal resin, when its moulded product is exposed in ultraviolet ray or the water for a long time, it is much more superior than the habitual composition that those do not contain these components, particularly, its be full of cracks occurred in after the longer time, and its glossiness hold-time is longer, its fading extent is lower.

Therefore, the polyacetal resin composite of Weather-resistant of the present invention is applicable to the material that requires remarkable anti-weather (light) aging field moulded product as all.It is specially adapted to be exposed in sunlight, rainwater and the air for example raw material of the internals of the exterior part of automobile (as external knob, fuel tank cap, wheel cover, wing and spoiler), automobile (as interior handle and setter handle), electrical equipment, photographic camera, other industrial parts, structured material and pipe, foreign material and household goods etc. of object for a long time as making.

Following embodiment will further specify the present invention, but they and do not mean that the present invention limited.

In following each embodiment, measure for example anti-weather of characteristic value (light) aging by following all methods:

1) Weather-resistant test (A and B):

Assess the variation of crack formation time and surface appearance with following two kinds of weather-o-meters.

Test A: surpassing acceleration weather-o-meter (SUV-W-11 in atmosphere and under 83 ℃; Iwasaki Electric Co, Ltd makes) in use the uviolizing test block, evaluate anti-day of test block suddenly aging then.

Test B: use can be sprayed the weather-o-meter (WBL-SUN-HCH of rainwater; By Suga Test Instruments Co, Ltd makes) use the uviolizing test block at 63 ℃, evaluate the Weather-resistant of test block then.

1. crack formation time:

Under predetermined condition, use uviolizing one period scheduled time of test block with above-mentioned weather-o-meter.With multiplying power is that 10 magnifying glass is observed the surface of test block to confirm the formation of be full of cracks.The crack formation time is meant the time opening of crack formation.This value more height shows that Weather-resistant better.

2. the variation of glossiness:

With weather-o-meter same as described above one period scheduled time is shone in test block.The variation of test block glossiness is observed in the irradiation back.The degree that changes is divided into five classes by following provisions.It is littler that numerical value shows more for a short time that glossiness changes, i.e. glossy loss is littler.

With digital variable angle glossometer (UGV-4D; By Suga Test Instruments Co, Ltd makes) the mensuration glossiness.The degree that glossiness reduces is decided according to the reservation situation of original gloss.

Intensity of variation is protected light rate (%)

More than 1 85

2 85-70

3 70-50

4 50-20

Below 5 20

2) Performance Evaluation:

Tensile elongation: press ASTM D638 method

Measure cantilever-type impact strength

(gap type): press ASTM D256 method and measure

Embodiment 1-16 and comparative example 1-12

Press shown in the table 1 weather (light) stablizer (B), acrylate resin (C) and oxyalkylene polymer (D), if necessary, and carbon black is added to polyacetal resin (A) (trade(brand)name: Duracon (M90); Polyplastics Co, the product of Ltd) in and obtain mixture.With 30 millimeters twin screw extruders this mixture is carried out melt kneading to make the granulous composition.With injection moulding machine pellet is molded into test block to assess its Weather-resistant and other characteristics then.In order to compare, repeat schedule of operation same as described above, different is to use weather (light) stablizer separately, perhaps be used in combination with it and acrylate resin (C) or with oxyalkylene polymer (D) (and, if need, also use with carbon black).

Annotate 1 B-1:2-(2-hydroxyl-3, two (a, the a-dimethyl benzyl) phenyl of 5-) benzotriazole

B-1:2-hydroxyl-4-oxygen benzyl benzophenone

Annotate 2 B-3: sebacic acid two (2,2,6,6-tetramethyl--4-piperidines ester)

B-4: Succinic acid dimethylester/1-(20 hydroxyethyl)-4-hydroxyl-2,2,6,6-tetramethyl piperidine polycondensate

Annotate 3 C-1: methyl-methacrylate resin (molecular-weight average is 60000)

C-2: methyl-methacrylate resin (molecular-weight average is 20000)

Annotate 4 D-1: polyethylene oxide (molecular-weight average is 20000)

D-2: polyethylene oxide (molecular-weight average is 50000)

D-3: poly-1,2 epoxy prapane (molecular-weight average is 60000)

Table 1

Embodiment

1 2 3 4 5 6 7 8

(A) polyacetal resin 84.4 84.4 84.4 74.4 77.4 64.4 84.4 74.4

Annotate 1 B-1 B-1 B-1 B-1 B-1 B-1 B-1

-

(weight %) (0.6) (0.3) (0.3) (0.3) (0.3) (0.3) (0.3)

(B) weather (light) stablizer

Annotate 2 B-3 B-3 B-3 B-3 B-3 B-3 B-3

-

(weight %) (0.6) (0.3) (0.3) (0.3) (0.3) (0.3) (0.3)

(C) acrylate resin is annotated 3 C-1 C-1 C-1 C-1 C-1 C-1 C-1 C-1

(weight %) (10) (10) (10) (20) (20) (30) (10) (20)

(D) oxyalkylene polymer is annotated 4 D-1 D-1 D-1 D-1 D-1 D-1 D-2 D-2

(weight %) (5) (5) (5) (5) (2) (5) (5) (5)

Carbon black (weight %)--------

Table 1 (continuing)

Embodiment

1 2 3 4 5 6 7 8

The crack formation time (hour) 80 60 150 180 150 240 140 170

Old 100 hours 22111111 of anti-weather

The voltinism test

(A) glossiness changed 200 hours 33212132

300 hours 55434243

The crack formation time (hour) 960 720 1,440 1,660 1,560 1,920 1,480 1880

Old 600 hours 11111111 of anti-weather

The voltinism test

(B) glossiness changed 1000 hours 23222111

2000 hours 45344221

Tensile elongation (%) 90 87 83 39 33 18 78 42

Cantilever-type impact strength (kilogram cm/) 4.4 4.8 4.2 3.1 2.6 2.1 4.2 2.9

Table 1 (continuing)

Embodiment

9 10 11 12 13 14 15 16

The crack formation time (hour) 180 160 130 130 290 350 280 180

Old 100 hours 11111112 of anti-weather

The voltinism test

(A) glossiness changed 200 hours 12221113

300 hours 33441115

The crack formation time (hour) 1,940 1,600 1,080 1,320 2,120 2,640 2,400 1020

Old 600 hours 11111111 of anti-weather

The voltinism test

(B) glossiness changed 1000 hours 11221112

2000 hours 33442114

Tensile elongation (%) 38 32 80 88 70 20 63 35

Cantilever-type impact strength (kilogram cm/) 3.0 2.8 4.1 4.2 3.6 2.4 3.5 4.1

Table 1 (continuing)

Comparative example

1 2 3 4 5 6

The crack formation time (hour) 40 35 35 35 60 80

Old 100 hours 333332 of anti-weather

The voltinism test

(A) glossiness changed 200 hours 554454

300 hours 555555

The crack formation time (hour) 420 400 380 400 600 720

Old 600 hours 222222 of anti-weather

The voltinism test

(B) glossiness changed 1000 hours 555534

2000 hours 555555

Tensile elongation (%) 31 33 74 95 25 14

Cantilever-type impact strength (kilogram cm/) 3.8 4.2 5.9 5.5 4.0 1.9

Claims

1, a kind of polyacetal composition, it comprises weather (light) stablizer of polyacetal (B) the 0.01-5% weight of (A) 45-98.89% weight, it is selected from benzotriazole category for one or more, benzophenone, the aromatic benzoate class, cyanoacrylate, N, the compound of N '-phenylbenzene oxalyl amine and hindered amines, (C) acrylate resin of 1-40% weight, it is the homopolymer or the multipolymer for mainly being made up of methyl methacrylate of methyl acrylate, and the polymkeric substance that (D) contains the oxyalkylene units of 2-8 carbon atom in its oxyalkylene units of 0.1-10% weight, it is selected from polyethylene oxide for one or more, poly-1, polymkeric substance in 2-propylene oxide and oxyethane/1,2 epoxy prapane multipolymer.

2, according to the polyacetal resin composite of the Weather-resistant of claim 1, wherein weather (light) stablizer (B) is for comprising one or more compounds that are selected from benzotriazole category, benzophenone, aromatic benzoate class, cyanoacrylate and oxalic dianilide class and the mixture of hindered amine.

3, according to the polyacetal composition of the Weather-resistant of claim 1, it contains the polymkeric substance (D) of 1-10% weight.